Clock with power failure indicating means



P 5 T. cooNRADT ETAL CLOCK WITH POWER FAILURE INDICATING MEANS 2 Sheets-Sheet 1 Filed June 4, 1955 INVENTORS TEALL COONRADT FRANCIS K FREUNDORFER A TORNEY Sept. 28, 1954 T. COONRADT ETAL CLOCK WITH POWER FAILURE INDICATING MEANS 2 Sheets-Sheet 2 Filed June 4, 1953 INVENTORS TEALL COONRADT FRANCIS K. FREUNDORFER BY ATTORNEY Patented Sept. 28, 1954 UNITED STATES PATENT OFFICE CLOCK WITH POWER FAILURE INDICATING MEANS Application June 4, 1953, Serial No. 359,482

2 Claims. 1

This invention relates to time indicating clock and more particularly, to illuminating and power failure indicating means for clocks provided with translucent dials.

Clocks of this type are electrically driven by means of a self-starting synchronous motor. In normal operation the clock dial is illuminated by a white light. In the event of a power failure the lamp will be extinguished and the clock will stop for the duration of the power failure. Upon the restoration of power, the clock will operate but will be slow by the amount of time that the power was off. A set of significantly colored lamps, usually red in color, will be energized and will serve to illuminate the clock dial and by the color of the dial will indicate that there has been a power failure. When the clock is manually reset to the correct time, manual reset means are also provided for transferring the dial illumination from red to white.

The principal object of the invention is to provide means which shall perform the function set forth, in an effective, unfailing and expeditious manner.

Another object of the invention is to provide a clock having a translucent dial with contrastingly colored dial illuminating means.

A further object of the invention is to provide means for resetting illuminating Iamps at the time that the clocks are reset to the correct time.

A still further object of the invention is to provide a power failure indicating means automatically operative and serving upon the resumption of power to illuminate the dial of the clock with a significant color.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Figure 1 is a view of an electrically operated clock equipped with dial illuminating lamps.

Figure 2 is a plan view of the clock showing the hand driving motor, the dial illuminating lamps, and the lamp reset control push button.

Figure 3 is a circuit diagram for the clock.

With reference to Figures 1 and 2, the clock comprises a translucent dial it) having suitable time indicating characters thereon, which is supported and attached to the case It by means of a holding ring 12. The dial it is arranged to be illuminated from behind by either a set of lamps I3 or a fluorescent tube M.

A self-starting synchronous drive motor I5 is attached to the dial Hi by means of the screws It. The motor is arranged to drive the minute hand I? and the hour hand it in a conventional timekeeping manner. The motor is is provided with a shaft is which extends through a hole in the bottom of case i l. Shaft it has a knurled portion lSa for manually resetting the clock hands l? and E8 to the correct position.

In the normal on-tiine operation of the clock, it is intended that the dial it will be illuminated by means of the fluorescent tube it. This provides a uniform illumination for the complete dial surface. Tube It is supported by suitable holding members 2%], which are in turn fastened to the brackets 2!. Brackets 2i are rigidly attached to the clock case i i Each of the brackets 2| is adapted to support a lamp [3. A plurality of lamps I3 are uniformly spaced behind the dial Iii. The lamps I3 are of a contrasting color, usually red, and serve after the event of a power failure to illuminate the dial it in a color contrasting with the illumination afforded the dial it in normal operation by tube M.

A conventional type of ballast 22 employed as a starting device for tube it is attached to the case H. A relay 23 utilized as a control element for the dial illumination circuitry is shown attached to one of the brackets 23. A push button 24 is mounted in the lower portion of the clocl: case it. The push button 24 provides a manual reset means for the dial illumination circuitry as will hereinafter be described.

Figure 3 shows the circuitry for control of the dial illumination. The synchronous driving motor 15 is connected with the alternating current supplied to terminals 25 and 26. In normal operation relay 23 will be energized. The circuit for holding relay Z3 energized is from terminal 25, through the contact points 23a in an energized position, the relay coil 23 to terminal 28. When relay 23 is energized, the circuit controlling tube i4 is completed. The circuit is from terminal 25, through the contact points 231) in the energized position, the tube i l and ballast 22 to terminal 26.

In the event of a power interruption the synchronous drive motor [5 will cease operating and. relay 23 will be de-energized. When the power is restored, the drive motor IE will become operative but the clock will be slow by the amount of time which elapsed during the power failure. The circuit to the power failure indicating lamps l3 will be completed. The circuit is from terminal 25, through the contact points 23b in the de-energized position, the parallel connected lamps I3 to terminal 26. The energization of the lamps !3 causes the dial H] to be illuminated in a significant color indicative of the event of a power failure. The colored illumination of the dial [6 will serve notice to persons observing the clock that the time indicated is not reliable.

The clock must be manually reset to correct time. The reset operation for the clock is accomplished by rotating shaft l9 until the clock hands I! and I8 correspond with the correct time. Push button 24 is then momentarily actuated and closes the energizing circuit for relay 23. The circuit is from terminal 25 through push button 24, the relay 23 to terminal 26. Once energized, the relay 23 will remain energized through the hold circuit from terminal 25, contacts 23a, relay 23 to terminal 26. The energization of relay 23 causes the circuit for tube M to be completed. The circuit is from terminal 25, through contact points 231) in the energized position, the ballast 22 in combination with tube Hi, to the terminal 26. Ballast 22 is employed in a well-known manner as a starting device for tube Hi. The circuit for tube I4 will remain energized until another interruption of power occurs.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

l. A power failure indicating device for a clock having a translucent dial comprising two sets of contrastingly colored lamps illuminated by the power source for said clock and mounted in close proximity behind said dial for illuminating said dial, a control relay, a reset device, circuit connections completed by said reset device for energizing said relay from said power source, a holding circuit completed by said relay to said power source to retain said relay energized independent of said reset device as long as the supply of current from said power source is continuous, circuit connections completed when said relay is energized for connecting one set of contrastingly colored lamps with said power source to illuminate said dial with a color indicative of a proper operating condition, circuit connections completed when said relay is deenergized for connecting the alternate set of contrastingly colored lamps with said power source subsequent to a power failure, whereby, upon resumption of power, said contrastingly colored lamps are illuminated to impart to said dial a significant color indicating the occurrence of a power failure.

2. A power failure indicating device for a clock having a translucent dial comprising contrastingly colored lamps illuminated by the power source for said clock and mounted behind said dial for indicating power failure and for illuminating said dial, a control relay, switching means controlled by said relay and having alternative positions as a result of the energize.- tion or de-energization of said relay, holding contacts closed by said relay when it is energized, a reset device, circuit connections completed by said reset device for energizing said relay from said power source, a holding circuit completed by said relay to said power source to retain said relay energized independent of said reset device, as long as said power source'is on, circuit connections completed by said switching means in one position when said relay is energized for energizing one of said contrastingly colored lamps to illuminate the dial and indicate by its color a continuous operating condition, and circuit connections to said contrastingly col ored lamps completed by said switching means in its other position when said relay is de-energized by the failure of said power source, whereby, upon resumption of power, the other of said contrastingly colored lamps is illuminated to impart to the dial a significant color to indicate an interruption in the power source.

References Cited in the file of this patent UNITED STATES PA'IENTS Number Name Date 1,469,946 Morrison Oct. 9, 1923 2,566,597 Cass Sept. 4, 1951 2,605,331 Gordon, Jr. July 29, 1952 

